The invention relates to an apparatus and method for separating solid particles and liquids from flowing gases.
Separators of this type are used predominantly in the intake air of internal combustion engines if increased contamination and/or the presence of liquid droplets are generally expected as, for example, in engines for farm machinery and construction machinery of all types, as well as in commercial vehicles. Usually, these devices are used as preliminary separators.
U.S. Pat. No. 3,064,411 discloses an apparatus which is intended to separate solids from a fluid medium and has the following characteristics. The cylindrical housing of the device tapers conically at its axial end faces, and the inlet and the outlet are disposed at the reduced diameters. An inlet guide vane is arranged on the inlet side and an outlet guide vane at the outlet side within the cylinder, which is tapered conically at both ends. Both guide devices are provided circumferentially at the respective ends of the cylinder and guide the flowing media through curved guide vanes into a rotational movement. In their axial spacing, the guide vanes are connected with one another by a centrally disposed cylindrical core of reduced diameter. The transition of the diameters between guide vanes and core at both ends is formed by a conical section. A reducing sleeve, which transitions into a cylindrical pipe, is mounted following the inlet guide device. This reducing sleeve constricts the cross-section of the rotating, flowing medium and accordingly leads to an acceleration, which results in an optimum deposition. The reducing sleeve ends centrally in the cylindrical housing, so that the rotating flow continues its path through a circumferentially enlarged space. Before it reaches the outlet guide device, the flowing air is received by an annular separating element, which once again has a reduced cross section, and passed through a conical element to the outlet guide device. In the center of the housing, a funnel-shaped discharge opening is provided, which guides the particles to a discharge pipe.
The incoming air flow is passed over the conical surface to the guide vanes and caused to rotate. Due to the subsequent constriction, the rotation is accelerated, and the centrifugal force accordingly is increased. Since the diameter increases once again in the direction of flow after the reducing sleeve, the particles are deposited against the outer wall of the housing. Since the rotating flow of air passes through only a portion of the separation chamber, a second, lesser rotational movement arises adjacent the surface of the housing. Due to the different flows, the precipitated particles can pass through the low-lying funnel leading to the discharge opening without being carried along by the main flow of air. The medium flows on over the conical casing surface to the outlet guide device, which converts it back to a linear flow as a result of the opposite direction of rotation of the guide elements.
A disadvantageous aspect of this apparatus is its high manufacturing cost, which is necessary due to the arrangement of the individual air-guiding elements. Furthermore, a high flow resistance is produced by the four-fold change in cross-section of the main flow.